Over the years the recording industry has strived for perfection but until very recently has come up short of its goal. Even in the old master recordings there is a fuzziness present that was not mitigated by the use of Dolby or multi channel recording techniques. Now with the use of high resolution digital techniques perfection is being approached. A good example of this is REFERENCE RECORDINGS RR-117 Lincolnshire Posy by Percy Grainger. It should be pointed out that the use of modern digital processing on the old master recordings still retains the totally unacceptable fuzziness. This technique has been widely practiced in the last 20 or so years with the result that there is a large number of unacceptable classical discs being sold even today.
If a recording is done correctly there is music content in each channel without distortion or noise. For material that is imaged between the speakers there must be musical material that is identical but generally at different levels in the two channels. The only exception to this is for imaging midway between the loudspeakers, in which case the signal level in the two channels is identical. If such a signal is presented to the system and then amplified at very low distortion, it remains for the loudspeakers to create an acoustical environment that preserves the original sound quality.
A way in which the conventional speaker is inadequate is that the air that must pass between the voice coil and the magnet has so little room that the velocity of the air flow becomes high and turbulent even for relatively low sound levels. This leads to a back pressure that presents twice on the dust cover for every cycle. The cone motion is influenced by this back pressure with two bad effects. First, at low frequencies where the cone motion is greatest, the back pressure is great enough to seriously limit the motion of the cone and thereby limit the base response. Secondly, a great deal of noise is generated due to the turbulence with the result that the sound signal contains much noise even when the driving electrical signal is of the highest quality.
An additional problem with the conventional loudspeaker is that air trapped behind the lower suspension is also a source of turbulence which must be dealt with.